The Type 1 Diabetes TrialNet Consortium was initiated in 2001 following completion of its predecessor, the Diabetes Prevention Trial-Type 1 (DPT-1). This network consists of 14 US and 4 international clinical sites. In addition, there are more than 200 US affiliate sites which perform subject screening, a Central Coordinating Center, and several TrialNet-associated laboratories. The goals of the TrialNet consortium are to prevent or delay the onset of T1D, to test interventions aimed at decreasing beta cell destruction and/or enhancing beta cell survival in persons with T1D with residual beta cell function, and the performance of mechanistic studies. The University of Minnesota (UMN) has been a DPT-1/TrialNet Clinical Center since the beginning. Throughout this history, UMN has been highly productive and engaged, contributing intellectually to project development and reporting, and actively participating in all aspects of each TrialNet project. The aims of this renewal grant are to continue the tradition of UMN as a high-quality, high-performing TrialNet Clinical Center in the critical areas of project development, screening, recruitment, treatment, follow-up, and reporting; to increase screening rates for detection of subjects at high risk for development of T1D by further developing and supporting UMN affiliates and by exploring general population screening within new UMN research facilities at the Minnesota State Fair; and to foster collaborations with new T1D researchers in the Upper Midwest region.